●The size is adjusted to match the width and thickness of 2x4 lumber, making marking easy. ●You can check 45° and 90° at the same time to prevent injuries. ●The short side of 2x4 lumber is 89mm, so you can easily divide it into equal parts of 1/2, 1/3, or 1/4. ● Comes with a screw hole guide that allows you to mark the location where the screws should be driven in. ●Comes with 150mm scale. ●Made of transparent polycarbonate resin, which makes it easy to see the wood and prevents it from being damaged.